This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. It has become increasingly clear that there are additional mechanisms additional to the sliding filament theory that contribute to the contractile properties of smooth muscle. Ourselves and others have proposed that remodelling of the cytoskeleton may explain the uniqie contractile properties exhibited by smooth muscle. The goal of this project is to determine the relationship of changes in organization of the cytoskeleton in the contracting A7r5 cell line to its contractile properties as well as contractile properties of vascular smooth muscle.